Ultrastructural features of myenteric ganglia of adult Wistar rats (Rattus norvegicus)

The ultrastructural features of the ganglia of the myenteric plexus exhibit changes according to the animal species. These myenteric ganglia in the duodenum of adult rats of the Wistar strain were characterized ultrastructurally in this work. Those ganglia were depicted as compact structures, composed of neurones and glial cells, forming a dense neuropil surrounded by a continuous basal lamina and collagen fibrils. Glial cell bodies were smaller and apparently more frequent than neuronal cell bodies, being morphologically distinguished by nuclear features. In the neuronal extensions granular and agranular synaptic vesicles of different sizes predominate, in addition to mitochondria and myelinized profiles. Gliofilaments were not observed on the glial extensions of the rats

Influence of delayed placement and dietary lysine levels on small intestine morphometrics and performance of broilers

This experiment studied the influence of delayed placement (HI) and digestible lysine level (DL) on the morphometrics of the intestinal mucosa and on the performance of broilers. A total number of 1,705 Cobb 500 male chicks were used in a completely randomized experimental design in a factorial arrangement with four HI (12, 24, 36 and 48h), and two DL level in the starter diet (1.143 and 1.267%), with four replicates and 55 birds per experimental unit. The amino acids methionine-cystine, threonine, and tryptophan were balanced according to the ideal protein (IP) concept. Small intestine morphometrics was evaluated using histology slides of the duodenum and jejunum. There was no interaction between HI and DL levels for any of the studied parameters. The 1.143% level of DL promoted better performance results at 21 and 42 days of age, as well as higher duodenum and jejunum crypt depth, and duodenum villi height at 21 days of age. HI negatively influenced the morphometrics of the small intestine during the starter phase, and the performance of broilers up to 42 days of age. There was no effect of the treatments on yolk sac utilization or abdominal fat percentage. It was concluded that the use of 1.143% DL and HI of 12 hours promoted better development of the small intestine mucosa up to 21 days of age, and broiler performance at market age

Morphologic and quantitative study of the myenteric neurons of the jejunum of malnourished rats (Rattus norvegicus) Estudo morfológico e quantitativo dos neurônios mientéricos do jejuno de ratos desnutridos (Rattus norvegicus)

We studied the effects of maternal proteic desnutrition on the neurons of the myenteric plexus of the jejunum of rats from Rattus norvegicus species. It was used litters of female rats which received diet with normal proteic level during gestation and lactation (group NN), normal diet during gestation and hypoproteic diet during lactation (group ND); hypoproteic diet during gestation and normal diet during lactation (group DN); hypoproteic diet during both gestation and lactation (group DD). After weaning all the animals received diet of normal proteic level until the 60th day of age, when they were killed. The jejunum of the animals was subjected to whole-mount preparations stained by the method of Giemsa and used for the morphologic and quantitative analyses of the neurons of the myenteric plexus. We verified that maternal proteic malnutrition does not cause decrease on the number of myenteric neurons per unit area of jejunum in rats, but elicits mechanisms which assure that, when the animal again receives normal proteic level diet (22%) there occurs storage of proteic material on the cytoplasm of the neurons, thus rendering them larger and strongly basophylic.<br>Estudamos os efeitos da desnutrição protéica materna sobre os neurônios do plexo mientérico do jejuno de ratos da espécie norvegicus. Utilizamos filhotes de ratas que receberam dieta com teor protéico normal durante a gestação e a lactação (grupo NN), dieta normoprotéica durante a gestação e hipoprotéica durante a lactação (grupo ND); dieta hipoprotéica durante a gestação e normoprotéica durante a lactação (grupo DN); dieta hipoprotéica durante a gestação e lactação (grupo DD). Após o desmame todos os animais receberam dieta com teor protéico normal até os 60 dias de vida ocasião em que foram sacrificados. Preparados de membrana do jejuno foram corados pelo método de Giemsa e foram utilizados para análises morfológicas e quantitativas dos neurônios do plexo mientérico. Verificamos que a desnutrição protéica materna não provoca redução no número de neurônios mientéricos por área do jejuno de ratos, porém desencadeia mecanismos que fazem com que quando o animal volta a receber dieta com teor protéico normal (22%) ocorra acúmulo de material protéico no citoplasma dos neurônios, o que os torna maiores e fortemente basofílicos

Balanced Caloric Restriction Minimizes Changes Caused by Aging on the Colonic Myenteric Plexus

Aging can promote significant morphofunctional changes in the gastrointestinal tract (GIT). Regulation of GIT motility is mainly controlled by the myenteric neurons of the enteric nervous system. Actions that aim at decreasing the aging effects in the GIT include those related to diet, with caloric restriction (CR). The CR is achieved by controlling the amount of food or by manipulating the components of the diet. Therefore, the objective of this study was to evaluate different levels of CR on the plasticity of nicotinamide adenine dinucleotide phosphate– (NADPH-) reactive myenteric neurons in the colon of Wistar rats during the aging process using ultrastructural (transmission electron microscopy) and morphoquantitative analysis. Wistar male rats (Rattus norvegicus) were distributed into 4 groups (n = 10/group): C, 6-month-old animals; SR, 18-month-old animals fed a normal diet; CRI, 18-month-old animals fed a 12% CR diet; CRII, 18-month-old animals fed a 31% CR diet. At 6 months of age, animals were transferred to the laboratory animal facility, where they remained until 18 months of age. Animals of the CRI and CRII groups were submitted to CR for 6 months. In the ultrastructural analysis, a disorganization of the periganglionar matrix with the aging was observed, and this characteristic was not observed in the animals that received hypocaloric diet. It was observed that the restriction of 12.5% and 31% of calories in the diet minimized the increase in density and cell profile of the reactive NADPH neurons, increased with age. This type of diet may be adapted against gastrointestinal disturbances that commonly affect aging individuals.São Paulo State University (Unesp) Institute of BiosciencesDepartment of Morphological Sciences Maringá State UniversityCentral Vivarium Maringá State UniversityCruzeiro do Sul UniversityLaboratory of Marine and Coastal Organisms Santa Cecilia UniversityDepartment of Physical Education São Judas Tadeu UniversitySão Paulo State University (Unesp) Institute of Bioscience